The Guy She Was Interested In Wasn't a Guy at All manga volume 3 features story and art by Sumiko Arai.

With Aya's encouragement and inspiration from a music festival they attend together, Mitsuki begins to pursue her passion for music in earnest! But when a certain video of her singing goes viral on social media, Mitsuki ends up becoming somewhat of a celebrity at school—and her newfound fame brings difficulties for both her and Aya…